Muscle massager



FIG. 1 is a perspective view of a muscle massager, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines shown in the drawings depict portions of the muscle massager that form no part of the claimed design. 

CLAIM The ornamental design for an muscle massager, as shown and described. 